To enhance the stability of the supercavitating vehicle caused by the nonlinear planing force between the cavitation and the vehicle, a cascade control method for the depth tracking was proposed based on the circle criterion theory and the Nelder-Mead algorithm. The mathematical model of the supercavitating vehicle and the circle criterion theorem were introduced. The cascade error state equation of the supercavitating vehicle was established based on the model, and the absolute stability of the inner-loop was studied using the circle criterion. The inner-loop feedback parameters were further optimized through the Nelder-Mead algorithm. The simulation analysis results show that the control method proposed in this paper is convenient for feedback parameter tuning, and can realize the accurate depth tracking effectively.